Almer mcduffie mcafee



A. M00. Mc AFEE.

MANUFACTURE OF HIGH GRADE LOW BO ILING PETROLEUM PRODUCTS.

APPLICATION FILED JAN.9, 1915.

is Q Patented Dec. 23, 1919.

. T FFEQ ALMER MCDUFFIE 'MGAFEE, OF YORK, Y. ASSIGNOR TO GULF REFININGCOMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF TEXAS.

MANUFACTURE or HIGH-GRADE LOW-BOILING PETROLEUM PRODUCTS.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Application filed January 9, 1915. Serial No. 1,375. A

To all whom it may concern Be it known that I, ALMER MGDUFFIE Mo- AFEE,a citizen of the United States, residing at New York, in the county ofNew York and State of New York, have invented certain new and usefulImprovements in the Manufacturing of High-Grade Low-Boiling PetroleumProducts, of which the following is a specification.

This invention relates to themanufacture of high-grade low-boilingpetroleum products; and it comprises a method wherein higher boilingpetroleum oils or products are subjected to a cracking operation toproduce vapors of lower boiling products, such cracking operation beingat ordinary pressure or under as much added pressure as may be desired;the vapors are led into contact with a heated body of oil containingaluminum chlorid, such body of oil being oil condensed from such vaporsor being oil from another source, or both; and the vapors coming fromsaid heated body are then condensed in a suitable manner; all as morefully set forth and described.

The fact that the commercial demand for the lower boiling petroleumoils, gasolene, and naphtha or solvent oils, such as the turpentinesubstitutes, is greater than that for the higher boiling oils has ofcourse led to the proposal of many methods for converting high boilinginto low boiling oils. The most common method now in use is crackingwhich involves heating high boiling residual oils or distillates to atemperature at which they will break up or dissociate. By the use ofpressure the temperature to which liquid oil can be heated is of courseincreased and the cracking operation is thereby rendered more productive of cracked low boiling oils and products. A greater yield ofgasolene can be obtained. In practice, the crude petroleum is firstfreed by ordinary distillation of the natural gasolene (if any) and.kerosene which it contains, and then the distillation is continued undercracking conditions and at a high temperature; often under highpressure. A further portion of cracked gasolene and kerosene appears asa result of this distillation; and under proper condltions a ratherlargepercentage of the residual oilcan be so converted into gasolene andkerosene. The same cracking operation for the production. of gasolenelsoften applied to gas oil and other low grade distillates.

These cracked distillates however are of comparatively low grade; theyare not nearly so desirable as the natural gasolene and keroseneobtained by simple di'stillation of crude oil. This low quality ismostly due to the fact that they are largely composed of unsaturatedoils or hydrocarbons; hydrocarbons which, chemically considered, do notcontain enough hydrogen to saturate the carbon. are foul-smelling, burnwith smoky flame and darken on standing or exposure to air. Purificationof these cracked distillates by the ordinary method adapted with naturaloils and distillates, that is, treatment with sulfuric acid, isexpensive since the loss of oil and'the consumption of acid areinordinately great. Unsaturated oils combine with sulfuric acid withreadiness.

Another method of producing low-boiling oils from high boiling oilswhich gives gasolene of much higher grade involves the use of aluminumchlorid. Aluminum chlorid exercises a number of distinct actions uponthe hydrocarbons which constitute petroleum oils and petroleum products.It is capable of producing intermolecular and intramolecularrearrangements, which may be utilized in making lower boiling oils fromhigher-boiling oils, as in making gasolene from gas oil, etc. Anotheraction is the production of saturated hydrocarbons from unsaturated withdeposition of carbon. When high boiling petroleum oils are admixed withaluminum chlorid and the mixture is kept at the distilling or boilingtemperature, say 47 0 F. or higher, a distillate is produced which,under proper conditions, is a clean, sweet, saturated gasolene requiringlittle or no treatment with acid to make a commercial high-gradematerial. Ordinarily treatment of the distillate with acid for thepurpose of removing unsaturated compouhds is neither needed nor used. Inorder to accomplish these results, the operation should be so conductedthat a partial refluxing of condensed vapors back to the boiling mixtureoccurs and the temperature of the vapors at the point where they leavethe vapor producing system to enter the final condensing system shouldnot be above 350 F. If the vapors reach the final condensing system at ahigher temperature,

Unsaturated oils not only is the condensate impaired by the resence ofundue amounts of high boiling raotions but aluminum chlorid (or itscompounds with the hydrocarbons of the oil) is also apt to pass overinto the condenser. This not only removes the chlorid from the placewhere it is needed but stops-up the condenser. Also the distillationshould be carried on comparatively slowly; the heating should be soconducted as to spread the distillation over, say, 48 hours.

The described method may be used for converting any higher boilingpetroleum oilv dry. As a rule about 5 percent. of aluminumchlorid,calculated on the weight of oil, is used, but greater or less amountsmay be employed. A charge of chlorid may be continuouslyemployed untilit is converted crudes, byinterrupting the disti lation after asubstantial amount of low boiling oils has will be pr cticall into a.granular coky mass of little activity and be then removed and replacedby fresh reagent. Charging and discharging may be continuous ordiscontinuous. If the temperature at the oint of vapor exit to thecondenser be' held around 350 F.,* the condensate willbe a mixture ofgasolene,-naphthaf and kerosene which may be redistilled to separate andobtain these, products; but if the vapor temperature be held somewhatlower, sa at about 300 F., the distillate i all gasolene. If the vaportemperature at t e exit from the vapor producing system be held stilllower, at, say,

200 to 250". F., a highly volatile gasolene of uniform character may beobtained. By

continuing the distillation of a charge of oil to the end about 85 percent. or more may be converted into gasolene, or gasolene, naphtha andkerosene, as the case may be; the 15 per cent. or so differencerepresenting gasand coke. Even when usin low grade been distilled overbut when a substantial amount of high boiling oil remains in the still,the latter is fit for the manufacture of high grade lubricants,medicinaloils, parafiin, etc., asphaltic constituents, sulfur, etc.,

having been removed or converted into other products. I

The action ofal'uminum chlorid on oils in thedescribed inethod is, asstated, twofold. It has a saturatin action, converting unsaturatedhydrocar one into saturated, and it also llae a converting or-breakingdown action by virtue of which it transforms high-boiling oils, underthe distillin conditions stated, into low-boiling oils. T e saturatingaction is attended with a deposition of carbon; the aluminum chloridfinally being converted into a coky sludge from which it may be regainedfor reuse by suitable methods (see McAfee Patent No. 1099096, grantedJune 2, 1914).. Other decarbonizing catalysts than aluminum chlorid maybe used, such as for exam 1e aluminum in the presence of hydrochlorleacid, aluminum in the presence of chlorin, aluminum bromid, ferricchlorid, zinc chlorid, .etc., but they are not generally asadvantageous.

By a modlfication of the described method I may also materially improvethe quality of these cracked gasolenes in other respects than theconversion of the unsaturated into the saturated hydrocarbons. There isa demand for gasolene distilling within. a narrower temperature rangethan that of ordinary gasolene which, as it now occurs on the market,may begin to distil at 120 F. and end at a distillin temperature of 350F.

In so doing I tace advantage not only of the property of aluminumchlorid of converting unsaturated into saturated bodies, but also of itsproperty of converting higher boiling oils into lower boiling. For thispurpose I operate at a-somewhat higher temperature in treatin themixture of gasolene and aluminum ch orid than that Just described. Thishigher temperature produces more or less distillation and I control thisdistillation in a special way. This treatment may not only be applied tothe commercial cracked gasolenes but also to the cracked distillatesfrom which these cracked gasolenes are made by redistillation. Thesecracked distillates be 'n to boil at about 120 F. and haveanal boilingpoint of about 500 F. or possibly above. To this end Imix the materialwith aluminum chlorid as before and heat to the boiling temperature ofthe mixture under such conditions as will permit a refluxing of vaporsofhigh boiling, or heavy, portions or fractions. The vapors may beallowed to pass to the final condensing system at a temperaturebetween.- 200 F. and 250- F. The product here is, as before, a cleansweet gasolene but it is of more uniform characteristics than theoriginal, having a closer distillationrange.

In the present invention I operate on the vapors coming from a petroleumstill, advantageously one in which cracking di'stil lation is beingperformed, and subject these vapors to the action of aluminum chloridimmediately after their formation. In such an embodiment of my process Imay crack a suitable high boiling oil in a suitable apparatus;advantageously using a pressure up to, say, 4 to Gatmospheres; that is,60 to .90 pounds. This pressure may be that due to the vapors formed inthe still or to vapors or gases pumped into the still into or over thedistilling mass. The oil treated may be a residual crude petroleum fromwhich low boiling fractions have been removed; or it may be one of thelow grade distillates sold as gas oil, solar oil, etc, or, but lessadvantageously, straight crude oil. The vapors leaving the still andpassing a suitable pressure reducing valve may be directly contactedWith aluminum chlorid in any suitable receptacle. This receptacle isbest heated although this is not always necessary. Under the describedconditions, high boiling constituents in the vapors con- .dense and forman oil pool or body containing the aluminum chlorid. The low-boilingconstituents of the vapors are converted in this bath or body ofaluminum chlorid-oil mixture into saturated products and pass onward toa suitable condenser to give gasolene. Between the aluminum chloridmixture and the condenser is interposed any suitable reflux means whichwill return vapors of aluminum chlorid, of high boiling oils, etc. Aspreviously stated, the temperature to be maintained at the entrance tothe condensing system may be between 300 and 350 F.; the precisetemperature depending upon the product sought. For very volatile, highlyuniform gasolene the temperature at this point is advantageously evenlower; say, between 200 and 250 F. The high boiling oil of the oil body,or aluminum chlorid-oil mixture, is constantly changing under theconvertingaction of the alumlnum chlorid, being converted into gasolenewhich distils over. New portions of high boiling oil condense and keepthe volume of the oil replenished.

In the described operation, substantially I am. treating the vapors froma cracking still or element'with aluminum' chlorid; I am interposing analuminum chlorid treat ment between the ordinary cracking still and theordinary condenser.

I may also combine the improvement of the cracked distillates with thealuminum chlorid method of producing gasolene heretofore described. Inthis embodiment of my invention I produce cracked oil vapors in themanner previously described and pass these vapors directly into a hotboiling mixture of high boiling oil and aluminum chlorid; this highboiling oil being from another source. For example, I may provide acharge of gas oil and aluminum chlorid in a suitable still and bring itup to the boiling point for the production of the described saturatedgasolene.- Another charge of gas oil is contained in an ordinarycracking still, which may beoperating under heavy pressure, and thevapors from this cracking operation are led directly into the boilingmass of oil and aluminum chlorid.

The saturating action of aluminum chlorid is here more rapid than itsgasolene-producing action and in this manner of operation withoutchanging the normal operation of the gasolene-producing still, so far asthe action of the aluminum chlorid upon the charge of high boiling oilthereln contained is concerned, I can materially increase its output. Amuch larger amount of gasolene vapor is delivered to the condenser in agiven time in using a given still. Part of this gasolcne comes fromthetransforming action of the chlorid upon the high boiling oil charge;part comes from the cracked vapors fed in; but it is all uniform, clean,good quality saturated gasolene,

The vapors from the cracking still are, as usual rich in high boilingoils vaporized at the high temperatures employed, and are also largelyunsaturated. In passing through the oil-chlorid mixture the high boilingoils are condensed and 10in the mixture while the unsaturated lowboiling compounds are saturated and pass on.

In the accompanying illustration I have shown, more orlessdiagrammatically, partly in elevation and partly in vertical section, anassemblage of apparatus elements for use in the described process. Inthis showing, element 1 is a cracking still or other source of crackedoil vapors of any'suitable construction and heated in. any ordinarymanner. It is provided with the gage 2 and the safety valve The vaporsproduced in the still pass through. the vapor line -l, past a throttlingor a pressure reducing valve 5 to an annular perforated pipe 6 situatednear the bottom of an aluminum chlorid still 7. As shown, this still isprovided with stirring means 8 carrying'chains 9. Within the still is abody 10 of a mixture of high boiling oil and aluminum chlorid. Vaporsfrom this still pass through the conduit 11 to air cooled condensingchamber 12, which operates to reflux aluminum chlorid vapors, etc.Beyond this chamber the vapors pass through conduit 13 to another aircooled reflux device 14, and thence through the conduit 15 to a thirdair cooled chamber 16. These latter two-chambers communicate at theirbottoms, respectively, through 17 and 18 with a conduit 19 leading backto the still. In this latter conduit is a depression 20 which serves asa trap. The inlet 21 scr'ves for introducing fresh oil. Manhole 22serves for introducing fresh aluminum chlorid, cleaning, etc. Themanhole 23 may be used incleaning the still, removing chlorid sludge,etc. The valve pipe 24 may be used for removing oil. Thediagrammatically shown furnace 25 serves for heating. The vapors whichleavethe last IlitlHBClsCllttll'lbG-l' (16) pass through conduit 26 pastthermometer 27 into a condenser of usual type 28 contained in thecooling tank 29.

In the use of the described apparatus the cracking still 1 may becharged with a body of any suitable petroleum material whether crudeoil, residual oil or a distillate oil, and heated until the pressureshown by the gage 2 reaches the desired point. The pressure may beadvantageously 60 pounds to 90 pounds, that is four to six atmospheres,or even higher. Pressures ranging up as high as 300 pounds may beemployed but ordinarily pressures of four to six atmospheres are better.Cracked gasolene vapors pass out from the still through 4, the pressurein the still being maintained by suitable manipulation of valve 5. Thevapors from'4 pass into the aluminum chlorid still or chamber 7 throughthe perforated pipe 6.

This still contains a charge ofaluminum chlorid. It may be fed with gasoil or other suitable oil through inlet 21 from time to time or instarting. Or the condensate from the cracked oil vapors may be reliedupon. In either event a pool 10 of a mixture of heavy oil andaluminumchlorid is formed.

This pool may be maintained at a distilling temperature by thediagrammatically shown firing means 25, or the temperature in still orchamber 7 may be kept up by the heat of the vapors from element 1.Element 1 in.

lieu of being a still may be a mere receptacle for cracked oil vaporsproduced elsewhere. V-ap'ors of saturated gasolene, both that producedby the conversion of the vapors from 4: and the conversion of the oil oftheoil body 10 pass upward through the elements 12, 14 and 16 from whichcondensates drain back to the chamber 7. The operation is so conductedthat the temperature of the vapors passing through 26. as shown bythermometer 27, is not above 350 F. or such temperature as will preventthe carrying. of aluminum chlorid into the condenser.

It may be much below this temperatureas previously stated. The vaporsgoing to exit from the distilling system at 26 pass into condenser 28"and give liquid low/boiling saturated products. As stated, the liquidgasolene here formed does not necessarily require'acid treatment to makeit marketable, being a substantially saturated product.

While I have hereinbefore more particularly described the application ofthis invention to the treatment of cracked oil vapors, I obtain many ofthe same advantages by treating other oil vapors produced by simpledistillation without steam. For example, oil vapors from distillingcrude petroleum in the ordinary way may be passed through a pool or bodyof a heated mixture of high boiling oil and aluminum chlorid. In sodoing, the lower boiling oils, so far as they are saturated, pass onwardto the condenser, while unsaturated low boiling oils, if any arepresent, are converted into saturated and also goto the condenser. Thehigh boiling portions of the oil vapors are condensed 1. In themanufacture of low boiling petroleum products of high grade the processwhich comprises subjecting a petroleum material to a cracking operationand subjecting the evolved vapors to the action of aluminum chlorid insuficient amount to convert unsaturated compounds into low boiling sat-I urated compounds.

2. In the manufacture of low boning petroleum products of high grade,the process which comprises subjecting a petroleum material to acrackingoperation and subjecting the evolved vapors to the action j ofaluminum chlorid in the/presence of a body of high boiling oil.

3. In the manufacture of low boiling petroleum products of high grade,the process which comprises subjecting a petroleum material to a hightemperature distilling operation and subjecting the evolved vapors tothe action of aluminum chlorid in the presence of a body of high boilingoil.

4. In the manufacture of low boiling petroleum products of high grade,the process which comprises subjecting a petroleum material to acracking operation and subjecting the evolved vapors to the action ofaluminum chlorid in the presence of a heated body ofhigh boiling oil.

5. In the manufacture of low boiling petroleum products of high grade,the processwhich comprises subjecting a petroleum material to a crackingdistillation and subjecting the vapors to the action of aluminum chloridin the presence of a heated body of high boiling oil from anothersource.

6. In the. manufacture of-lowboiling petroleum products of high grade,the process which comprises distilling a high-boiling oil in admixturewith aluminum chlorid and during, the distilling operation passingthrough the boiling body of such mixture a. current of cracked oilvapors.

7. In the manufacture of low'boiling petroleum products of high grade,the'process which comprises distilling a high boiling oil in admixturewith aluminum chlorid and during the distilling operation passingthrough the boiling body of such mixture a current of oil vapors fromanother source.

8. The process of making saturated gasolene which comprises distilling abody of high boiling oil under cracking conditions, passing the vaporstherefrom into a chamto produce cracked gasolene vapors, passingsaidvapors into a heated chamber containing aluminum chlorid and intocontact with said aluminum chlorid, and withdrawing and condensingvapors from said chamber.

10. The process of making saturated gasolene which comprises distillinga body of high boiling. oil under high pressure, re-

. leasing the pressure on the vapors, passing said vapors into a chambercontaining aluminum .chlorid and into contact with said aluminumchlorid, and Withdrawing and condensing vapors from said chamber.

11. The process of making saturated gasolene which comprises distillinga body of high boiling oil under a pressure of four to six atmospeheres,releasing the pressure on the vapors, passing said vapors into a chambercontaining aluminum chlorid and into contact with said aluminum chlorid,and withdrawing and condensing vapors from said chamber.

12. In the production of saturated gasolene, the process which comprisesestablishing and maintaining a boiling body of a mixture of high boilingoil and aluminum chlorid while constantly removing and condensinggasolene Vapors therefrom and constantl introducing vapors of crackedgasolene t iereinto.

13. In the production of saturated low boiling petroleum products, theprocess which comprises establishing and maintaining a boiling body of amixture of high boiling oil and aluminum chlorid while constantlyremoving and condensing vapors of low boiling products therefrom andconstantly introducing vapors of cracked oil thereinto.

14. In the production of saturated gasolene, the process which comprisesestablishing and maintainin a boiling body of a mixture of high boi mgoil and aluminum chlorid while constantly removing and condensinggasolene vapors therefrom at a temperature not above 350 F. andconstantly introducing vapors of cracked gasolene thereinto.

In testimony whereof, I afiix my signature in the presence of twosubscribing witnesses.

ALMER MoDUFFIE MGAFEE.

Witnesses:

K. P. MOELROY, GEORGE G. MGDANIEL.

